The objectives of this research project are to: 1) Study calcium and zinc metabolism in isolated islets and the interrelationship of calcium and zinc metabolism to insulin secretion; 2) apply a subcellular technique for isolation of specific islet cell enriched fractions: plasma membrane, secretory granule, mitochondria, and microsomal for determining the binding and interaction of calcium and zinc; 3) determine the role of the trace elements: Cr ions, Cd ions, Cu ions, Pb ions on insulin release and islet cell metabolism and 4) determine the interaction of calcium, zinc, and other trace elements on the dynamics of polymerized and depolymerized tubulin in relation to insulin secretion from isolated islets.